System of air control



SHEES SHEEY l.

`FILEDMAR.1, 1919.

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Jan. 2, 1923.

R. HOFSTETTER.

SYSTEM or AIR CONTROL.

FILED MAR.1.|9|9L 2 SHEETS-SHEET 2.

Patented Jan, 2, w23.,

Tannat onTTan l sTa/Tres PATENT caerse.

ROBERT HFSTETTER, 01? CIBICAGO, ILLINOIS, ASSIGNOR T0 EL'LLINOIS TQIL WEIKS,

K 01E' CHCAGO, JILLNGIS,

A CORPORATION 0F ILLINIS.

svsirnn or ara common Application led March 1,1919. 4 Serial No. 279,993` A To all whom t may concern.'

Be itknown that I, ROBERT Hors'rn'r'rnn, a citizen of the United States, and a resident of Chicago, in thecounty of Cook and State of lillinois, have invented certain new and useful lmproved Systems of Air Control, of which the following is a description, reference being had tothe accompanyin drawings, which form a part of my specication.

My invention relates to systems for controlling air, or other fluidl mediums, employed in the operation of mechanisms; 'the invention relating more especially to air conrllled devices, such as lathe chucks and the The' object of my inyention is to provide means whereby the consumption of air, or other Huid medium, employed in the operation of mechanisms or devices, will be greatly lessened, with the result that a great 4saving is obtained and the'expense of opera-A tion, thereby materially reduced; the invention consisting of a system contemplating suitable valve mechanisms whereby thev power-imparting medium, during one stroke ofthe operating cycle of the devices-namely thereleasing or return stroke-will be employed at a greatly lower pressure than the pressure employed during the other or forward and operating stroke of the operating cycle; namely, either employing the expansion of low pressure secondary air to return the piston; or employing low pressure live air, or employing the expansion of low pressure secondary air and low pressure live air; with the result that the cost of Operation of air-controlled devices or mechanisms, as at piresent' employed, will be materially lessene My invention will be more fully understood and its advantages comprehended from the accompanying drawings, wherein Figure 1 is a partial side and sectional', as well as a more or less diagrammaticview of means adapted to carry out my improved.

system shown applied to an air-operated lathe chuck. A

Figure 2 is a diagrammatic view of means for utilizing a moditication of my inven-v tion. l

Figure 3 is a similar View .of means for carrying out another modification of my improved systeln. i

My improved system, in its more specific adaptation, contemplates the introduction into the air-or other iiuid medium-conveying lines, of multi-ported reducing, releasing and check valves, and in certain instances a reversing-valve, in connection with air operated-lathe chucks, stationary chucks, expanding lathe mandrels, vices,l countershafts, arbor presses and the like; and the invention may have expression in different mechanical forms, as is evidenced by the drawings accompanying this specification, without, however, departing from the spirit of my invention as expressed in the claims hereto appended.

1n the particular exempliication of' the invention, as illustrated in Figure 1, it is shown applied to an air-operated chuck shown at 10 wherein the jaws are controlled by an air-operated spindle 11 slidably arranged-in a suitable sleeve or shell; the end of the spindle 11 being disposed in the air cylinder 12y and provided with a suitable .Huid-operating medium, is conveyed by' suitable valved linesand mechanisms to the couplings or inlets 14 and 15; the one being usually adapted to admit the air, by means of a passage through the piston and spindle and radial ports in the latter, so as to be eective on the forward side of the cyliiider 12 and thereby drive theV piston 13 backwardly, causing the jaws of the chuck to come into gripping relation with the material operated on; while the other coupling communicates directly with the near or rear y side of the cylinder and therefore rearward of the piston, so that the latter will be forced forward into chuck-releasing position.

As the construction' of the chuck, cylinder, and connections between the chuck and piston, as well as the construction of the airinlets or couplings secured to the cylinder,

present invention, a

form no part of my detailed description and illustration of said mechanisms need not be given. y The more or less dlagraatlc illustra-K' tion of my improved system for the reduction of air consumption, contemplates a sult-l able source of compressed air supply which is vconveyed into the system through pipe l 16; the admission of the air being controlled by a three-way valve, as at 17. The valve 17 connects with a lpipe or line 18 which connects with a multi-way reversing valve as at 19, whereby the course of the air in its passage tc and from cylinder 12 is controlled; the valve being operable in` any suitable manner, while the casing or shell thereof has-communication with the couplings or inlets 14 and 15 by means of ipes or conduits 20 and 21, respectively. 1th the three-way valve 17 positioned as shown in Figure 1, live air under-'high -pressure is allowed to pass into line 18 and through the multi-ported reversing valve 19, which is shown positioned to establish communication with conduit 20. With this situation, the air is conductedby suitable passages through the cylinder, piston and spindle into the sleeve 11 and therefore for- .ward of the piston 13 in cylinder 12, causing the piston to move backwardly or to the left in Figure 1, and thereby closing the chuck; while the space in the cylinder 12, rearward of the piston 13,-that is on the left hand side of the piston as illustrated in Figure A1,-is open to the atmosphere and any. air in the space permitted to exhaust from the cylinder or escape into the atmosphere by means `of coupling 15, conduit 21v and thence through port 23 of valve 19, into pipe .24. Pipe 24 is shown leading to a cylinder or 'chamber 25, which is also provided with a pipe 26 provided with a threeway valve 27 similar in construction and way valve`27 is shown positioned so as to establish communication between pipe v26 and4 exhaust pipe 28, whichis open tothe atmosphere.

In order to release the chuck-jaws, the air-or other medium-must, of course, be admitted to the opposite or left hand side of the piston 13, as shown in Figurey 1, while the pressure forward of the piston must b e reduced.

It is the purpose of my improved system,

as 'exemplified in Figure 1, to utilize the.

secondary air, namely the air previously employed in driving Athe piston into chuckclosing positlon, for moving the piston in the opposite or chuck-releasing position; so that expansionpof the previously employed air-or other medium-will be further utilized before it is allowed to exhaust or escape. This is accomplished by yproper operation of the vthree-way valves 17 and 27, which are operatively c connected together by an operating rod-29 which is pivotally secured to the levers of the valves 17 and 27 so as to cause them to operate in unison. Proper end lof the cylinder against the action of position to three-way` valve 17. The threeoperation of connecting rod 29, namely in a downward direction in Figure 1, will give valves 17 and 27 a quarter turn and bring the ports or passages of both into com` munication with a connecting line or pipe 29. and with pipes 18 and 26, respectively. p The high pressure air, forward of the pistonll3-namely, to the right thereof in Figure 1,-will-then be caused to flow out of cylinder 12 through coupling' 14 having communication' with that side of the cylinder 12, thence through conduit 20 to valve 19, through passage 30 of the valve into pipe 18, through valve 17 into line 29?, which is shown provided with a suitable check-valve at 31, operable only in the direction of fiow from valve 17 to valve 27.

The high pressure air will cause checkvalve 31 to move off its seat and permitthe air to ,continue through pipe 29a, into valve. 27 and thence into line 26 and small cylinder or chamber 25 on through conduit 24valve 19-c-onduit 21-coupling 15, into the space back of piston 12. It will be understood that the quarter turngiven valves 17 and 27 will cut off communication with conduits 16 and 28, respectively. The admission of the air into small cylinder 25 at the up'per end of the cylinder as shown in Figure 1 causing the pressure to become such that the pressure of spring 32 on the opposite side of the piston 33 is overcome, because of the area. 'of piston 33 relative to the valve later described, and piston 33 forced to the lower spring .32, which is thereby compressed. Piston 33 is connected by stem 34 with4 a valve 35 mounted in a casing 36 located in line 18.

Assho'wn in the drawing, valve 35 will not only be maintained on its seat-*when the pressure in cylinder 25 has notireached a predetermined degree,-by spring 32, but also by the air pressure in pipe 18 and casing 36. The equalizing of pressures in cylinder 25 and line 18, provided with valve 35, causes valve 35 to move ofi' its seatand'thus permit air in line 18 and casing 36 to escape into the atmosphere through-ports 37 formed in casing 36 intermediate of the seat of 115 valve and the small cylinder L25. The unseatlng of valve 35 will permit the air remaining in cylinder 12 forward of piston 13 and in line 18 `to escape into the atmosL phere through ports 37; while the air in'120 lines 21,24 and 26 willbe held back by check-valve 31. As soon as the pressure in line 18-decreases, the piston 13 in cylinder 12 will start forward into the position shown in dotted lines in Figure 1,-in which position the chuck is in releasing conditionv because the air inlines 24 and 21' is now at a higher presure than that in lines 20 and 18; the latter vhaving been reduced toatm'ospheric pressure.

' neenoee by giving reversing valve 19 a quarter turn so as to bring lthe straight port. or passage 38'into communication 'with line-18 and conduit 21, thus permitting the live air or pressure-inducing medium entering by means of three-.way valvev 17 to flow` into cylinder l2 at the left of piston 13. With this operation ot valve 19, a second Straight port or passage 39 is brought into position so as to establish communication'between conduit 20 and line 24, when the loipd'eration and control of the air pressures by the various elements will be the same as previously described, eX- cept as tol points of original introduction into cylinder 12.

4The saving of airfor other operating medium-accomplished by the foregoing described system, over the Iamount of air con-` sumption required in devices as at presentemployed, is at least fifty/ per cent; due to the tact vthat secondary air is utilized for completing the cycle of operation; Whereas 4 the methodI of operation at present employed, necessitates the introduction'ot fresh air under pressure to both sides of the pis-A ton; while the air is then allowed to exhaust into the atmosphere.

lin the exemplification of the invention, as disclosed in the more 'or less'diagrammatic view shown in Figure 2, li show a cylinder 40 provided with a piston 41 while opposite Conduit 47 communicates with a three-way' valve 48, which may establish communica! tion withthe atmosphere at 49and also with an inlet conduit 50. The reversing' valve 46 also communicates'with a'conduit. 51 leading to port 44 at the opposite end of the cyl- '-inder; and: the reversing valve 46 is also ada ted to establish communication with a -con uit 52 leading to a three-way val-ve 53 having communication with the atmosphere at 5t anawith a conduit 55. Conduit 55 is'.

provided with a pressure-reducing'valve at 56; while the'opposite endl of conduit '55 connects witliinlet conduit 50.

The two three-way -valve`s48 and 53 are intended to be operated by means 'of avl'ever 57 so as to operate in unison; the val-ves be-l .f-end of the cylinder.

ing so positioned thatA when valve 48 establishes communication between inlet conduit 50 and conduit 47 leading to reversing valve 46 and thereby admitting a high pressure w charge, three-way valve 53 will be in position to 'establish communication between conduit 52 and the atmosphere port 54 so as to exhaust the pressure in lines '51 and 52, when reversing valve 46 is in the position shown in Figure 2. With this position of the valves, it is apparent that .the air under pressure entering conduit 50, passing through three-way valve 48, conduit 47 and conduit 45 will be admitted through port 43 into the right hand end of cylinder 40 and induce the initial stroke of the operating cycle of the piston 41; while any air in the' left hand end of cylinder 40 may exhaust through port' 44, conduits `51 and 52 and valve 53 into the atmosphere through port 54. Under these conditions the piston 41 will be forced to the left end ot'cylinder 40 until it reaches the stop 42 at the left` hand ln order to drive piston 41 back to the right hand side of cylinder 40, namely intowhat may be termed the work-releasing position and. therefore requiring a. less air pressure, leverf57 is actuated so as to give three-way valves 48 and 53 a quarter turn, thereby bringing the passage-ways or ports of valve 48 into communication with conduit 47 and air port 49; while the passage-ways of va1ve`53 will have been moved so as to establish communication between conduits 52 and 55 and thereby shutting off the atmosphere communicating port 54. Conduit 55, being in communication with, the inlet conduit 50, will be charged with live air but at a reduced pressurel predetermined by means of'a reducing valve 56, so that the 'operation of the threeway valve -just described will permit the air, at a reduced pressure, in conduit to pass through valve 53, conduits 52'and 51 and through port 44 into the left hand end of cylinder 40; while the air pressure in the right hand side of. cylinder 40 will be permitted to exhaust through conduits 45, 47 and three-way valve 48 lout into the atmosphere through port 49; with the result that the piston 4l will be driven'back tothe right hand side of the cylinder until -it contacts withstop 42.

The reversing valve 46,- like reversing .i

valve 19 previously described, is. provided with a number ofpassages or ports which will permit communication to be established between conduits 45 and 52 and between conduits 47 and 51. When the straightpassages ot reversing valve 46 are in communication with the conduits as just stated, the

high pressure air passing through three-way l valve 48 will be conveyed through conduit 47 into conduit 51 and through port 44 into the-lett hand side of cylinder 40; while the cylinder, the reversing valve 46 may be 'omitted fand in that event conduits may be employed for directly conveying the airfrom three-Way valve 48 into port 43 of the cylin` der 40 and from three-way valve 53 into port 44 at the left hand end of cylinder 40.

Withthe construction just described, the

air consumptionnecessary for completing a.

cycle of operation'is somewhat greater than' the air consumption necessary forv complete -ing the cycle of operation with .the con` struction shown in Figure 1; because in the construction shown in Figure 2 live air ata low vpressure is employed for returning the piston in the air-operated cylinder, namely during the non-operating'or return stroke of the cycle'of operation. The quantity of air-or other operating mediumnecessary-with the mechanism disclosed in Figure 2 for completinga cycle of operation, is, however materiallyless than the consumptionoi airnecessary in the method of operation at present employed -in 'connection with air-operated or controlled devices, -`wherein live air, under e ual pressure. is admitted at both ends of t e air-cylinder for completing a c cle of operation,v l

In the modi cation of my improved sys-l tem as disclosedl in rFigure 3, the mechanism isshown lin a Smore or less diagrammatic manner and illustrates an air-cylinder 58 provided with a piston 59 adapted to travel lengthwise of. the cylinder; theends ofthe l latter being' preferably'provided with stps as at 42, 42 Awhereby the ltravelo'f the piston is limited so as lto leave air ports. 60 and" 61 uncovered at the endsof the. cylinder. Air Y' port 60 communicates with a conduit 62 vpreferably leading to-a reversing valve 63 which is shown providedwith multi-ports or passages.V The valve' 63 is positioned in Figure '3 sovas to establish communicatlonbetween conduit 62 and line 64. Line 64 iS shown, provided with a 'three-wayvalve 65;.

and the line, beyondrthe valve'65, isV adapted in Figure 3, shows conduitf64 open 'to the Aatmosphere and therefore would permit any.

air at the right hand end of cylinder 5,8.t'o

- exhaust into the atmosphere. lThe threeway valve 65 upon receiving 'aquarter turn l is adalpted toestablishv communication between ne 64and a line 66T Line 66 is shown branched and xvprovided with -acheck-valve at 67I whereby communication may be es-A' :.tablished between line 66 and a line 79,

namely at-a point Where line 68 is rovided with a three-way valve 69. The t ree-way valve 69 in the figure is shown positioned lso as to shut oil" communication between line 68 and the branch of line 66 provided with the check-valve 67. Line 66 is also provided with a two-way valve 70 arranged in ad- Vance ofv a reducingvalve 71 which has communication with line 68 by means of a line 72. Line 68 isintended to connect with a suitpiston 75 is controlled bymeans of a suitable spring 77 and in turn maintains valve v74 on its seat so that the air passing through line 79 cannot escape into the atmosphere. Assuming that the high air .pressure is permitted to flow into line 68, |the air, with the positionin ofthe valves as shown'in the figure, will ow through three-way l valve 69 and'be conveyed through reversing.. valve 63 into conduit l73-and thence into the vleft hand end of 'cylinder v58. With the valves as shown, the right hand end of cylinder 58 is open to atmosphere by means of'conduit 62, line 64 and three-way valve 65, so that the high pressure air entering the left hand end of the cylinder willcausepiston 59 't0- travel to the right in the position shown.

Reducing valve -71- is set vso as to reduce jtheflive compressed air -to a predetermined -degree ofpressure commensurate with the natureofwork or operation intended to'fbe performed by the air controlled device on the return stroke thereof. Inforder to rev lverse the 'operation of the piston 59, it becomes-'necessary to operate three-way valves 65 and' 69 andthe two-way valve 70. The three valves mentioned are controlled by means Yo fa suitable lever, as at 78, which enables the three valvesfto be operated in. f

unison; causing. the valves .to be given. a

qnarterturn to establishjthe desired'connectlons.-` The two-Way valve., 70, however, has such connection withglever 78 that it will Ynot`'bei.positioned until ls li htly after the three-way-valves 65 and 69. ave lcompleted their operatiomlin other words, the three- .125-v Way. valves. 65 v and 69 are intended to be l positi'enedso'as to establish communication- .between'line'64fand line .66'.and between line.

'68 and the check-valvabranch of line 66 before two-way valve 7 0 establishes communication between the line 66 and the reducing valve 71. Upon completing the operation of the valves 65,69 and 70, as just debranch of line 66. As soon as the pressures `in lines 64 and 79 become about equal, the

piston 75 (because of its reater area than the area 'of valve 74) will e forced against the action of spring 7 7 and therefore move valve od of its seatfand permit the remaining air in line 7 9 to discharge into the atmosphere, thus causing the air remaining in line 64 and connections (which air cannot escape on account of check-valve 67) to push the piston 59 toward the left.

As soon as the pressure in line 64 and'co-nnections drops to a certain value (due to the movement of pist-on 59 towards the left) reducing'valve 71 opens and adds live air of a lower pressure than prevails in line 68, to

the secondary air in lines 66, 64 and thus completes the return stroke of the piston.

The operation just described completes a cycle of operation of the air-controlled piston 59, which has aga-in been brought back to original or normal position.

Where the operation heretofore described is to be reversed, namely where the high pressure is to be initiallydischarged into the righthand end of cylinder 58, this may be accomplished by a quarter turn Aof reversing valve 68 which will bring the curved passages Aor portsof the valve into Vsuchv position as to establish communication between inlet line 68 and conduit-62; while the other curved passage or port of reversing valve 63 will have established communication between line 64 and conduit 7 3. in the modification just described, the consumption of live air is somewhat greater than the consumption with the c"`onstruction disclosed in Figure 1, but the saving, over the methods at present employed, is

which, as is clearly evident from the ltort-igoing description and the drawings, results in a great saving of air in the operation of air controlled devices; Vand while ll believe the q means diagratically illustrated and herein described as best adapted for practicing my invention, l do not wish to be understood as confining myselt1 to any spe-A ciic construction of mechanism.

`What l 1wish to secure by Letters Patent is l. A system of air control for air-oper-- kinlet line and the atmosphere when pressure in the second line reaches a predetermined' degree.

2. A system of air control for air-operating devices, comprising aninitial inlet line,

a second line, means whereby the high pressure supplied to the initial inlet line may be shut oli' and whereby a portion of the air pressure fromv the initial inlet line may be conveyed through said second line to complete the cycle of operation of the devices and the pressure 'in the initial inlet line redced to atmospheric pressure, and automatic means for conveying a-reduced charge of live air into said second line to supplement the charge. of secondary air admitted from the initial inlet line. Y

3.- A system'of air control for air-operated devices, comprising a pair of lines,

means whereby'both of said lines are selectivelyadapted to be placed in communicatitonwith a source of air-supply and also adapted to be placed-in communication with the atmosphere, and means whereby communicatiton between the two linesv and communication between one of the lines and the atmosphere may besimultaneously effected through a single actuatin of a portion of said means. A

4. A system of air-control for air operated devices, comprising a pairof air lines, means whereby both of said lines are`selectively adapted to be placed in communication with a source of air supply and also adapted to be placed in communication with the atmosphere,- means whereby communication between the two lines and between one of the lines and the atmosphere maybe si-v multaneously effected through a single actuationof a portion of said means, and means intermediate of both lines whereby the initial flow of air may be reversed.

.. 5. A system of air control for air 'operated devices, comprising a pair of air lines, means whereby both of said l1nes` are selecltween the two lines and between one of the Vitnesses:

tively adapted to be placed in communicaa portion of said means, and means interme- 10 tion with a source of air supply and also diate of the two lines, operable by theA inadapted to be placed in communication with crease pressure in one of said lineswwhereby the atmosphere, means intermediate of both the other line is opened to atmosphere,v

lines whereby the initial flow of air may be reversed, means whereby communication be- OB ERT HOFSTETTER' lines and the atmosphere may be simultane- F'. A. FmRELL,

-ously effected through a single actuation of G. HEIDMAN. 

